WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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Department: search.filters.department.İzmir Institute of Technology. Food EngineeringInstitution Author: search.filters.institutionAuthor.Çiftçioğlu, Muhsin

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Now showing 1 - 4 of 4
  • Article
    Citation - WoS: 21
    Citation - Scopus: 32
    Separation of Whey Components by Using Ceramic Composite Membranes
    (Elsevier Ltd., 2006) Erdem, İlker; Çiftçioğlu, Muhsin; Harsa, Hayriye Şebnem
    Ceramic supports were prepared from alumina powder and dip-coated with zirconia sol. The ceramic composite membranes prepared were characterized with respect to their microstructure/pore structures. The supports were 40% porous of which 87% were open pores. The average particle size of the sol particles was 35 nm. The prepared membrane has good protein lactose separation properties with a relatively high protein content (PR ∼80%) and with relatively low lactose retention (LR ∼7%). The permeate flux value was around 40 l/m2h. These results indicate the possibility of the preparation of ceramic composite membranes for separation of whey components with higher yields.
  • Conference Object
    Citation - WoS: 8
    Citation - Scopus: 12
    Mechanical Properties of Hydroxyapatite Composites Reinforced With Hydroxyapatite Whiskers
    (Trans Tech Publications, 2004) Şimşek, Deniz; Çiftçioğlu, Rukiye; Güden, Mustafa; Çiftçioğlu, Muhsin; Harsa, Hayriye Şebnem
    Sintering and mechanical behavior of pure and hydroxyapatite (HA) whisker reinforced HA composites were investigated in this work. Pure and composite samples were prepared by using a commercial powder and whiskers prepared by molten salt synthesis. The dry-pressed samples were sintered in the 800 and 1300°C range. The effect of whisker-addition on the mechanical properties of HA was investigated through compression and hardness testing. Compressive strength and fracture strain were observed to increase by the addition of whiskers.
  • Conference Object
    Citation - WoS: 10
    Citation - Scopus: 13
    Preparation and Characterization of Polylactide-Hydroxyapatite Biocomposites
    (Trans Tech Publications, 2004) Gültekin, Naz; Tıhmınlıoğlu, Funda; Çiftçioğlu, Rukiye; Çiftçioğlu, Muhsin; Harsa, Hayriye Şebnem
    In the present study, the preparation and characterization of polylactide-Hydroxyapatite(HA) composite films for biomedical applications have been studied. The effects of number of parameters such as polymer type, HA loading, surface modification and its concentration on the mechanical and microstructural properties of the composites were investigated. Poly-L-Lactide and 96/4 Poly(L-Lactide co D-Lactide) copolymer-HA composites containing 10-40 wt% HA particles have been prepared by solvent casting technique. The HA powder was synthesized by precipitation technique. Interfacial interactions between HA and polylactide polymer were modified to improve filler compatibility and mechanical properties of the composites by surface treatment of the HA with two different silane coupling agents; 3-aminopropyltriemoxysilane (AMPTES) and 3-mercaptopropyltrimethoxysilane (MPTMS) at three different concentrations(0.5-2 wt%). Silane treatment indicated improvements in the mechanical properties of the composites compared to the untreated HA loaded polylactide composites. Tensile test results showed that the maximum improvement in the mechanical properties of the composites was obtained for PLA composites containing 1 wt% aminofunctional silane treated HA and 0.5-wt% mercaptopropyltrimethoxy silane treated HA for PDLA composites. Scanning electron microscopy studies also revealed better dispersion of silane treated HA particles in the polymer matrix.
  • Conference Object
    Citation - WoS: 5
    Citation - Scopus: 5
    Preparation of Ceramic Composite Membranes for Protein Separation
    (Trans Tech Publications, 2004) Erdem, İlker; Çiftçioğlu, Muhsin; Harsa, Hayriye Şebnem
    Ceramic supports were prepared from fine alumina and zirconia powders by dry-pressing and slip-casting. These supports were heat treated in the 1100° - 1200°C temperature range and dip-coated with ceramic sols prepared from alkoxides by using sol-gel methods. The average sol particle sizes were measured as 3-7 nm for zirconia and 30-40 nm for alumina by laser scattering technique. The optimum heat treatment temperature range was determined as 500°-600°C for dip-coated membranes by using TGA (thermo gravimetric analysis) results. The microstructure of the ceramic composite membranes was investigated by SEM (Scanning electron microscope). The clean water permeability (CWP) of the membranes was tested by using deionized water in a filtration set-up. Separation experiments were performed with bovine serum albumin (BSA, Stokes diameter: 7 nm) solution and whey to determine the protein separation capacity of the composite membranes. The CWP of the dry pressed alumina supports heat treated at 1100°C was found to be higher than the permeability of the slip-casted zirconia supports heat treated at 1200°C. The protein retention of the slip-casted zirconia support was determined as 60% by using UV-Vis spectrophotometer (Abs. at 280nm). A protein retention value of 96% was achieved for whey after the modification of the support with dip-coating. The permeate flux was 40 L/m2hour for dry-pressed alumina support dip-coated with zirconia sol calcined at 500°C.